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Whalen MR, Chang KJ, Jones AB, Rivera G, Worthington AM. Fluctuating Asymmetry in the Polymorphic Sand Cricket ( Gryllus firmus): Are More Functionally Important Structures Always More Symmetric? INSECTS 2022; 13:insects13070640. [PMID: 35886816 PMCID: PMC9319220 DOI: 10.3390/insects13070640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 02/01/2023]
Abstract
Simple Summary Asymmetry in bilateral structures occurs when animals experience perturbations during development. This fluctuating asymmetry (FA) may serve as a reliable indicator of the functional importance of a structure. For example, locomotor structures often display lower levels of FA than other paired structures, highlighting that selection can maintain symmetry in traits important for survival or reproduction. Species that have multiple distinct morphs with unique behaviors and morphologies represent an attractive model for studying the relationship between symmetry and function. The sand field cricket (Gryllus firmus) has two separate morphs that allow us to directly test whether individuals maintain higher levels of symmetry in the structures most vital for maximizing fitness based on their specific life strategy. Longwing (LW) individuals can fly but postpone reproduction until after a dispersal event, whereas shortwing (SW) individuals cannot fly but begin reproducing in early adulthood. We quantified FA across a suite of key morphological structures indicative of investment in growth, reproduction, and flight capability for males and females across the morphs. Although we did not find significant differences in FA across traits, as predicted, locomotor compensation strategies may reduce selective pressures on symmetry or developmental patterns may limit the optimization between trait form and function. Abstract Fluctuating asymmetry (FA) may serve as a reliable indicator of the functional importance of structures within an organism. Primary locomotor structures often display lower levels of FA than other paired structures, highlighting that selection can maintain symmetry in fitness-enhancing traits. Polyphenic species represent an attractive model for studying the fine-scale relationship between trait form and function, because multiple morphs exhibit unique life history adaptations that rely on different traits to maximize fitness. Here, we investigated whether individuals of the wing polyphenic sand field cricket (Gryllus firmus) maintain higher levels of symmetry in the bilateral structures most vital for maximizing fitness based on their specific life history strategy. We quantified FA and directional asymmetry (DA) across a suite of key morphological structures indicative of investment in somatic growth, reproduction, and flight capability for males and females across the flight-capable longwing (LW) and flight-incapable shortwing (SW) morphs. Although we did not find significant differences in FA across traits, hindwings lacked DA that was found in all other structures. We predicted that functionally important traits should maintain a higher level of symmetry; however, locomotor compensation strategies may reduce the selective pressures on symmetry or developmental constraints may limit the optimization between trait form and function.
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Naniwa K, Aonuma H. Descending and Ascending Signals That Maintain Rhythmic Walking Pattern in Crickets. Front Robot AI 2021; 8:625094. [PMID: 33855051 PMCID: PMC8039156 DOI: 10.3389/frobt.2021.625094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/01/2021] [Indexed: 12/04/2022] Open
Abstract
The cricket is one of the model animals used to investigate the neuronal mechanisms underlying adaptive locomotion. An intact cricket walks mostly with a tripod gait, similar to other insects. The motor control center of the leg movements is located in the thoracic ganglia. In this study, we investigated the walking gait patterns of the crickets whose ventral nerve cords were surgically cut to gain an understanding of how the descending signals from the head ganglia and ascending signals from the abdominal nervous system into the thoracic ganglia mediate the initiation and coordination of the walking gait pattern. Crickets whose paired connectives between the brain and subesophageal ganglion (SEG) (circumesophageal connectives) were cut exhibited a tripod gait pattern. However, when one side of the circumesophageal connectives was cut, the crickets continued to turn in the opposite direction to the connective cut. Crickets whose paired connectives between the SEG and prothoracic ganglion were cut did not walk, whereas the crickets exhibited an ordinal tripod gait pattern when one side of the connectives was intact. Crickets whose paired connectives between the metathoracic ganglion and abdominal ganglia were cut initiated walking, although the gait was not a coordinated tripod pattern, whereas the crickets exhibited a tripod gait when one side of the connectives was intact. These results suggest that the brain plays an inhibitory role in initiating leg movements and that both the descending signals from the head ganglia and the ascending signals from the abdominal nervous system are important in initiating and coordinating insect walking gait patterns.
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Affiliation(s)
- Keisuke Naniwa
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Hitoshi Aonuma
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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Bent AM, Ings TC, Mowles SL. Anthropogenic noise disrupts mate searching in Gryllus bimaculatus. Behav Ecol 2018. [DOI: 10.1093/beheco/ary126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Adam M Bent
- Department of Life Sciences, Faculty of Science and Engineering, Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK
| | - Thomas C Ings
- Department of Life Sciences, Faculty of Science and Engineering, Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK
| | - Sophie L Mowles
- Department of Life Sciences, Faculty of Science and Engineering, Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK
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Fukutomi M, Someya M, Ogawa H. Auditory modulation of wind-elicited walking behavior in the cricket Gryllus bimaculatus. ACTA ACUST UNITED AC 2015; 218:3968-77. [PMID: 26519512 DOI: 10.1242/jeb.128751] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/20/2015] [Indexed: 11/20/2022]
Abstract
Animals flexibly change their locomotion triggered by an identical stimulus depending on the environmental context and behavioral state. This indicates that additional sensory inputs in different modality from the stimulus triggering the escape response affect the neuronal circuit governing that behavior. However, how the spatio-temporal relationships between these two stimuli effect a behavioral change remains unknown. We studied this question, using crickets, which respond to a short air-puff by oriented walking activity mediated by the cercal sensory system. In addition, an acoustic stimulus, such as conspecific 'song' received by the tympanal organ, elicits a distinct oriented locomotion termed phonotaxis. In this study, we examined the cross-modal effects on wind-elicited walking when an acoustic stimulus was preceded by an air-puff and tested whether the auditory modulation depends on the coincidence of the direction of both stimuli. A preceding 10 kHz pure tone biased the wind-elicited walking in a backward direction and elevated a threshold of the wind-elicited response, whereas other movement parameters, including turn angle, reaction time, walking speed and distance were unaffected. The auditory modulations, however, did not depend on the coincidence of the stimulus directions. A preceding sound consistently altered the wind-elicited walking direction and response probability throughout the experimental sessions, meaning that the auditory modulation did not result from previous experience or associative learning. These results suggest that the cricket nervous system is able to integrate auditory and air-puff stimuli, and modulate the wind-elicited escape behavior depending on the acoustic context.
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Affiliation(s)
- Matasaburo Fukutomi
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Makoto Someya
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Hiroto Ogawa
- PREST, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Selective forces on origin, adaptation and reduction of tympanal ears in insects. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 201:155-69. [DOI: 10.1007/s00359-014-0962-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 10/28/2014] [Accepted: 10/31/2014] [Indexed: 10/24/2022]
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Lucas KM, Mongrain JK, Windmill JFC, Robert D, Yack JE. Hearing in the crepuscular owl butterfly (Caligo eurilochus, Nymphalidae). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:891-8. [DOI: 10.1007/s00359-014-0933-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/20/2014] [Accepted: 08/12/2014] [Indexed: 10/24/2022]
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Marsat G, Pollack GS. Bursting neurons and ultrasound avoidance in crickets. Front Neurosci 2012; 6:95. [PMID: 22783158 PMCID: PMC3387578 DOI: 10.3389/fnins.2012.00095] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/11/2012] [Indexed: 11/13/2022] Open
Abstract
Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2's spike train consists of clusters of spikes - bursts - that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing - the auditory receptor - already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2's sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles.
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Affiliation(s)
- Gary Marsat
- Department of Cellular and Molecular Medicine, University of Ottawa Ottawa, ON, Canada
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Yager DD. Predator detection and evasion by flying insects. Curr Opin Neurobiol 2012; 22:201-7. [PMID: 22226428 DOI: 10.1016/j.conb.2011.12.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 12/12/2011] [Accepted: 12/17/2011] [Indexed: 11/29/2022]
Abstract
Echolocating bats detect prey using ultrasonic pulses, and many nocturnally flying insects effectively detect and evade these predators through sensitive ultrasonic hearing. Many eared insects can use the intensity of the predator-generated ultrasound and the stereotyped progression of bat echolocation pulse rate to assess risk level. Effective responses can vary from gentle turns away from the threat (low risk) to sudden random flight and dives (highest risk). Recent research with eared moths shows that males will balance immediate bat predation risk against reproductive opportunity as judged by the strength and quality of conspecific pheromones present. Ultrasound exposure may, in fact, bias such decisions for up to 24 hours through plasticity in the CNS olfactory system. However, brain processing of ultrasonic stimuli to yield adaptive prey behaviors remains largely unstudied, so possible mechanisms are not known.
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Affiliation(s)
- David D Yager
- Department of Psychology and Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD 20742, United States.
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The auditory system of non-calling grasshoppers (Melanoplinae: Podismini) and the evolutionary regression of their tympanal ears. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010; 196:807-16. [DOI: 10.1007/s00359-010-0560-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 07/06/2010] [Accepted: 07/07/2010] [Indexed: 10/19/2022]
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Fullard JH, ter Hofstede HM, Ratcliffe JM, Pollack GS, Brigidi GS, Tinghitella RM, Zuk M. Release from bats: genetic distance and sensoribehavioural regression in the Pacific field cricket, Teleogryllus oceanicus. Naturwissenschaften 2009; 97:53-61. [PMID: 19777200 DOI: 10.1007/s00114-009-0610-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 09/01/2009] [Accepted: 09/09/2009] [Indexed: 10/20/2022]
Abstract
The auditory thresholds of the AN2 interneuron and the behavioural thresholds of the anti-bat flight-steering responses that this cell evokes are less sensitive in female Pacific field crickets that live where bats have never existed (Moorea) compared with individuals subjected to intense levels of bat predation (Australia). In contrast, the sensitivity of the auditory interneuron, ON1 which participates in the processing of both social signals and bat calls, and the thresholds for flight orientation to a model of the calling song of male crickets show few differences between the two populations. Genetic analyses confirm that the two populations are significantly distinct, and we conclude that the absence of bats has caused partial regression in the nervous control of a defensive behaviour in this insect. This study represents the first examination of natural evolutionary regression in the neural basis of a behaviour along a selection gradient within a single species.
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Affiliation(s)
- James H Fullard
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada.
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ter Hofstede HM, Killow J, Fullard JH. Gleaning bat echolocation calls do not elicit antipredator behaviour in the Pacific field cricket, Teleogryllus oceanicus (Orthoptera: Gryllidae). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:769-76. [DOI: 10.1007/s00359-009-0454-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 05/26/2009] [Accepted: 05/29/2009] [Indexed: 10/20/2022]
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Narbonne R, Pollack GS. Developmental control of ultrasound sensitivity by a juvenile hormone analog in crickets (Teleogryllus oceanicus). JOURNAL OF INSECT PHYSIOLOGY 2008; 54:1552-1556. [PMID: 18938172 DOI: 10.1016/j.jinsphys.2008.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 09/19/2008] [Accepted: 09/19/2008] [Indexed: 05/26/2023]
Abstract
Cricket ears are sensitive to ultrasound as well as to lower, cricket-like sound frequencies. Ultrasound stimuli evoke negative phonotaxis in flying crickets, a behavior that has been interpreted as a defensive response against predation by echolocating bats. A recent study on a wing-dimorphic species, Gryllus texensis, showed that short-winged individuals, which are incapable of flight, are less sensitive to ultrasound, but not to lower sound frequencies, than their long-winged counterparts. The developmental decision to develop as a long- or short-winged individual is made during the last two larval instars, and there is some evidence suggesting that juvenile hormone (JH) has an instructive role, such that high levels of JH result in short-winged individuals. We show that treatment of last-instar larvae of a monomorphic long-winged species, Teleogryllus oceanicus, with a JH analog causes a decrease in sensitivity to ultrasound, but not to the lower sound frequency used for intraspecific communication.
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Affiliation(s)
- Rémi Narbonne
- Department of Biology, Mcgill University, 1205 Avenue Docteur Penfield, Montreal, QC H3A 1B1, Canada
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Forsythe SE, Leinhos HA, Bandyopadhyay PR. Dolphin-inspired combined maneuvering and pinging for short-distance echolocation. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 124:EL255-EL261. [PMID: 19062795 DOI: 10.1121/1.2960936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The biorobotic emulation of swimming and flying animals carrying out short-distance echolocation while maneuvering is considered. A simple and lightweight sonar for use on a small, maneuverable underwater vehicle for short-distance echolocation is explored. This sonar has four sensors and uses broadband, high-frequency signals to echolocate. The frequency-time characteristics of these signals are compared to those of bats and dolphins. The biosonar is paired with a biologically inspired, maneuverable, underwater vehicle, the combined use of sensors and maneuverability being analogous to animal behavior. Homing experiments have been carried out in an acoustic test facility where identification and localization of multiple targets is based on fusion of acoustic returns from multiple pings.
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Wimmer K, Hildebrandt KJ, Hennig RM, Obermayer K. Adaptation and selective information transmission in the cricket auditory neuron AN2. PLoS Comput Biol 2008; 4:e1000182. [PMID: 18818723 PMCID: PMC2527132 DOI: 10.1371/journal.pcbi.1000182] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 08/08/2008] [Indexed: 11/18/2022] Open
Abstract
Sensory systems adapt their neural code to changes in the sensory environment, often on multiple time scales. Here, we report a new form of adaptation in a first-order auditory interneuron (AN2) of crickets. We characterize the response of the AN2 neuron to amplitude-modulated sound stimuli and find that adaptation shifts the stimulus–response curves toward higher stimulus intensities, with a time constant of 1.5 s for adaptation and recovery. The spike responses were thus reduced for low-intensity sounds. We then address the question whether adaptation leads to an improvement of the signal's representation and compare the experimental results with the predictions of two competing hypotheses: infomax, which predicts that information conveyed about the entire signal range should be maximized, and selective coding, which predicts that “foreground” signals should be enhanced while “background” signals should be selectively suppressed. We test how adaptation changes the input–response curve when presenting signals with two or three peaks in their amplitude distributions, for which selective coding and infomax predict conflicting changes. By means of Bayesian data analysis, we quantify the shifts of the measured response curves and also find a slight reduction of their slopes. These decreases in slopes are smaller, and the absolute response thresholds are higher than those predicted by infomax. Most remarkably, and in contrast to the infomax principle, adaptation actually reduces the amount of encoded information when considering the whole range of input signals. The response curve changes are also not consistent with the selective coding hypothesis, because the amount of information conveyed about the loudest part of the signal does not increase as predicted but remains nearly constant. Less information is transmitted about signals with lower intensity. Sensory systems have the ability to adapt to changes in the environment. In a quiet room, the nervous system is very responsive, so that even a whisper can be easily understood. In contrast, the perceived loudness on a crowded street will be reduced to prevent an overload of the nervous system. Two different hypotheses have been proposed to explain how the nervous system achieves this adaptation. According to one idea, all present sensory signals are equally enhanced, so that the whole range of input signals is reliably represented. On the other hand, the aim of the nervous system may be to extract the most important parts of the acoustic signal, for example, an approaching car, and thus abolish the irrelevant rest. To address which of these two principles is implemented in the auditory system of the cricket, we investigated the responses of a single auditory neuron, called interneuron AN2, to different sound signals. We found that adaptation actually reduces the amount of encoded information when considering the whole range of input signals. However, the changes were also not in agreement with the idea that only the most important signal is transmitted, because the amount of information conveyed about the loudest part of the signal does not increase. Thus, we here report the unusual case of a reduction of information transfer by adaptation, while in most other systems reported of so far adaptation actually enhances coding of sensory information.
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Affiliation(s)
- Klaus Wimmer
- School of Computer Science and Electrical Engineering, Technische Universität Berlin, Berlin, Germany.
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FLYING CRICKETS HEAR ULTRASOUND BETTER. J Exp Biol 2007. [DOI: 10.1242/jeb.011775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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